Process of burning cement, gypsum, &amp; c.



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(Applicgeion mea Ap'r. 2s, 1900.)

No. 678,4l2 vPanama :my la, mol.

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PHJIIESS 0FA BURNING CEMENT, GYP-SUM, :Appximim fue@ Apr. 23, 1900.) (No Modql.) Y

2 sheets-sheet 2.

` UNITED STATES PATEN OFFICE.

WILHELM LEssING, or GESECKE, GERMANY;

bnocl-:ss oF BURNING CEMENT, GYPsuM, ato.

SPECIFICATION forming' part of Letters Patent N0.`678,412, dated July 16, 1901. @puatron mea April 2s, 1900. serial No. 14,036. (No Speimens.)

To all whom it may concern:

Be it known that I, WILHELM Lussino., a subject of the Emperor of Germany, residing at Gesecke, Westphalia, Germany, have invented a new and useful Process of Burning Cement, Gypsum, or the Like, of which the following is a specification.l

Revolving furnaces for this purpose require, of course, an inner jacket of ireproof material.-A When the material passes through in pieces, each piece rubs against the fireproof entirely worn away and has to be replacedin order to prevent the metal jacket of the furnace from being burned. If, however, itis de- A sired to completely calcine cement or the like in an inclined revolving furnace, it is neces- Sary t0 move the'material through very slowly or to cause it to pass successively through several such revolving furnaces until the degree of heat requiredfor complete calcnation is reached, so that in this case also the slag's melt together and have to be broken and ground when cool. -The latter effect of smelting together is produced in a still greater degrec if the raw material is introduced into the furnace in form of powder instead of pieces in order to save the .tireproof ljacket. Material in the form of powder as a far greater tendency to cake under -the influence of high temperature than materials in pieces, as is known. Burning powdered material in such furnaces had, therefore, the further disadvantage that caked material adhered to the inner jacket of the furnace and that through the continual accumulation of larger and larger quantities of `the adhesive substance the orifice of the furnace was entirely closed andino more material could be put in. With this method, likewise, the heat of the gases of combustion escaping from the furnace by the chimney remained unutilized. Suggestions forthe utilization of these gases for the pregases of combustion, and, on the other hand, the burned material is not sutciently cooled, as the current of air which is intended to cool it is itself already considerably heated, and therefore not capable of absorbing much more heat. It is also obvious thateven when the burned material is cooled by means of fresh air in the manner hereinbefore described the cooling is by no means complete and that a larger proportion of the heat of the material Y (about two-thirds) remains unutilized. jacket, so that in a short time the latter is.

The object of the present inventionis va process for continually burning cement, gypsum, or the like, in which alsoa revolving furnace is used and the air sucked in by the furnace is intensely heated in advance by be-y ing employed for coolingvthe burned material, but which process differs very considerably from all hitherto-known methods of burning, in` that the raw material is introduced after it has been ground into a revolving furnace,which only brings it approximately to a white heat, and is then transformed, still in a powdered condition, to a high-shaftfurnace, in which it trickles slowly downward between suitabl y-arrau ged impedij ments-.such as, for instance, conesagainst a column of flame, and is thus completely burned without being baked together into a compact mass. It is then caused tomove against the current of air which supplies thev are arranged in such a manner that they arey heated in order to produce steam by the still very hot burned material, and by thus withdrawing heat from .the latter cool it entirely. The cooling process is -f urther accelerated thereby, so that the burned materialleavs the drums at the placewhere freshwater for producing steam enters. To render the product ready for transport and use, it is then only necessary to pulverize it finely.v Bythe present process the heat of the escaping gases is also utilized to a far greater extent thanA was the case hitherto, these gases alsobeing conducted through inclined cylinders,

thereby drying the unground raw material,

I' or, if that'ls unnecessary, heating steam-producingapparatusj In the annexed drawings theentire plant necessary for carrying out the present proc. ess-is represented.l Figurel is a longitudinal section of the'env tire furnace arrangement-s.` .Fig. 2 is a front 'view ofthe furnace; and Fig. 3, a section.

. A*through the middle'of the revolving furnace,

' j showing the manner in. which it is suspended. Fig. 4 .is a plan. View of the entire furnace plant.; Fig. 5 is av section of the revolving Thebroken raw material is introduced vided with longitudinal ribs, which Aat each revolution carry the raw material upand let it fall again, and thus continually expose' it.

. to the'hot current which passes through the drums from the'furnaced until the raw' maing ground. From thedrums the raw mate-4 rialfalls on lhe.incline.e, which ends in the terial has become porous and suitable for beshaftof an elevator. AThe ra'w material is .then raised by means of elevators, crushed,

- introduced through the funnel f into the furand ground. The ground material is then "nacejd, through which it is made to pass in Athe .usualmannen .material is passed to theshaft-furnace In theupper part of the latter a cone n or the From the furnace d the like is provided, which'disperses the ground material evenly and breaks its fallto some extent. Through the pipe Z heated `gasis conducted'tothe shaft-furnace and through the "cylinder k heated air. `lower part of the shaft-furnace and the hot These mingle in the mixture ot' air' and gas feeds an ascending column of fla-me, which prevents the ground material from descending ,too rapidly, and enters the' revolving furnace al.v According to requirements a mixtureof hot air and gas can be introduced into the furnace d through the pipe rm. As has already been mentioned,

-qnentlythe column of llame moves against the groundburned 'material is dispersed. andi trickles downward in thefurnace t'. Conse- -the material,`by which means the latter 'is maintainedfor a longer period at incandescent; heat and is completely burned without thepo'ssibility of its caking.

Like the cylinders b and c and the furnace d, the cylinder k is inclined, audits interior surface is also provided with longitudinal i -lifting up and dispersal of the material by ribs. It is of considerable length. At the moment'of entering this cylinder k from the shaft-furnace the material has attained the highest degree of temperature required. The

the' longitudinal ribs of the cylinder 7c causeI the smallest particles of the material to vcome `into contact with the current of fresh air,

whichenters through the holes o, and l also cause the said current of air to become heated and the material to move forward till it reaches the holes o, through which and the funnel u it falls into the drums 0.

7 The holes o can be madelarger or smaller, according to requirement-s, by means of suitable sliding devices.

Inside of the drums 'v steam-producing apparatus are provided-in the presentinstance, revolving tubular. boilers j. -These are some` The burned y what inclined and adjustable. material cools against .the boiler-tubes containing water and gradually moves in consequence of the revolving vmotion toward the holes -1 through which its falls, completely cooled, and isthen. transferred to the grinding and shifting machine. In order to further the forward movement of the aterial in the -drums @,the interiors of the'| atter are likewise provided with longitudinal ribs. These ribs liftthe material andfthej let it fallback again. 'lhe heat of themate 'al being cooled .gradually converts the wate in the boilers ,into steam. The steam is then conducted by the tubes or -the liketo a stearnfaccumu# Vlator and can then be utilizedv for driving the engine-employed.

In order to secure the complete utilization of `th'e gases of. combustion, the latter can be passed from thedrums b and c to a'third rev volving drum', in which they are usedto 'dry some material, such as marl, clay, or the like. Before thegases escape into the chimney roo lthe dust produced by this drying processI is .deposited ina special dust-receptacle.

- Instead'. of the drums c, and s, horizontal steam-producers can of course be provided,

which are hea-ted by means ofthe gases escap ing from the-furnace, so that in this casealso x the gases ofA combustion are lutilized.

Having now described my invention', what I claim as new, and desire to protect by Letters Patent, is

ing nements, gypsum, &c., which consists in' grinding the raw material and heating this product to a white heat, dropping it downwardly against a column-of dame, and,then utilizing it in its.. intensely-heated condition Irs' for generating steam to be used vfor the treatment of further material, substantially as and in the manner specified.

2. The process for burning cements, gypsum, te., which consists in warmingand-drying broken raw material, vthen grinding and heatingand slowly dropping against a column of re,'then cooling and utilizing the result#y ing heat for generating steam and for'the-preliminary Warmingof the material,'substantially as set fort Berlin, 1900.

' y-WILHELlr-I.Lessard'.

Inpresenceof'- WOLDEMAR HAUPT,

HENnY Hnsrnm Germany, this 24th dayof'lMarch, l.

no 1. The herein=descri bed process for burn- 

